Major crack needs filling

[poolballboy]

Hi forum

We are moving Into an old office building and when removing some panels from a wall discovered a major crack that had been fixed badly. The filler used was falling out and crumbling.

The crack ranges in size from 5mm right up to 50mm and big chunks of plaster have dropped out also.

The crack obviously came about due to subsidence 15 years ago. The building report and inspection show the property to be sound and no more movement has been seen for the pAst 15 years.

What I need to know is how to fill this crack properly so it won't crumble and drop out again?

Thanks

Andy

Untitled

• poolballboy
• 14 Nov 2012
• 1

Untitled

• poolballboy
• 14 Nov 2012
• 1

Untitled

• poolballboy
• 14 Nov 2012
• 1

 

[NickB_99]

The crack obviously came about due to subsidence 15 years ago. The building report and inspection show the property to be sound and no more movement has been seen for the pAst 15 years.

What I need to know is how to fill this crack properly so it won't crumble and drop out again?

I guess if it was diagnosed as subsidence 15 yrs ago, that an insurance claim was probably made to fix - wondering whether they should have tidied up the large internal cracking too. Maybe that's where it got covered up with paneling!

It looks like it has some metal reinforcement behind (lath) on top of the brick already. The plaster finish around it doesn't look too great either - middle pic is very wavy and the original finish doesn't look very smooth.

A suggestion - you need to cut back the plaster a reasonable amount either side of the crack (e.g. 20cm each way) with a stanley knife.

Then the original lath may need cutting and a new section putting in (as it looks like it's snapped in places during subsidence).
Cover/fill with a suitable undercoat plaster e.g. Bonding or Hardwall, building up in 2 coats.
Can either leave a couple of mm's space to fill with multi-finish. (Use the surrounding plaster as a guide for you getting it level, then maybe scrape a little out to allow for the 2mm), or fill flush, scrim tape over join and either reskim wall, or skim a wider area and blend in.
I think in some cases it's easier to get a full wall reskimmed than patch in, but I don't know how big the wall is etc and your skills.

 

[roughcaster]

Newbee 99 is right, it does look like wire lath that's been plastered over.
It would be helpful if you would cut away some of the plaster either side of the cracked area, take a photo, and upload it to let us see the substrate/surface underneath the wire lath.